Publications

ectopic expression of tropomyosin promotes myofibrillogenesis in mutant axolotl hearts.	expression of tropomyosin protein, an essential component of the thin filament, has been found to be drastically reduced in cardiac mutant hearts of the mexican axolotl (ambystoma mexicanum) with no formation of sarcomeric myofibrils. therefore, this naturally occurring cardiac mutation is an appropriate model to examine the effects of delivering tropomyosin protein or tropomyosin cdna into the deficient tissue. in this study, we describe the replacement of tropomyosin by using a cationic liposo ...	1998	9853962
retinoic acid and thyroid hormone may function through similar and competitive pathways in regenerating axolotls.	the objective of this study was to determine whether thyroid hormone (th) would interfere with retinoic acid (ra), which proximalizes axolotl larvae regenerate limb pattern. ra and th are ligands for members of the steroid hormone thyroid hormone nuclear binding protein superfamily which form functional homodimers, but may also form stable heterodimers with the rxr protein and may recognize identical dna sequences. th alone does not affect limb pattern but induces metamorphosis in regenerating a ...	1998	9846384
expression of msx-2 during development, regeneration, and wound healing in axolotl limbs.	msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. we have identified the axolotl homolog of msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. as in limb buds of higher vertebrates, axolotl msx-2 is expressed in ...	1998	9846383
expression of msx genes in regenerating and developing limbs of axolotl.	msx genes, homeobox-containing genes, have been isolated as homologues of the drosophila msh gene and are thought to play important roles in the development of chick or mouse limb buds. we isolated two msx genes, msx1 and msx2, from regenerating blastemas of axolotl limbs and examined their expression patterns using northern blot and whole mount in situ hybridization during regeneration and development. northern blot analysis revealed that the expression level of both msx genes increased during ...	1998	9846382
comparative analysis of gnrh neuronal systems in the amphibian brain.	we have investigated the gnrh-ir neuronal systems in the brain of the oviparous urodele, triturus vulgaris, ovoviviparous urodele, salamandra salamandra, and viviparous caecilian, typhlonectes compressicauda, and have reexamined xenopus laevis, ambystoma mexicanum, and rana esculenta. results showed that mgnrh neuronal system was diffused along the medioventral telencephalon and diencephalon with the numerical preponderance of gnrh cell bodies in the rostral mediobasal telencephalon in t. vulgar ...	1998	9843639
interspecies variations in oral epithelial cytokeratin expression.	the aim of this study was to determine the degree to which the epidermis and oral epithelium of species other than man express cytokeratin (ck) intermediate filaments, which are markers of epithelial differentiation. fixed, wax-embedded samples of skin, buccal mucosa and gingiva from rhesus monkey, marmoset, cow, sheep, pig, ferret, hamster, axolotl and trout were tested for ck expression using a panel of antihuman ck antibodies and an immunoperoxidase procedure. human skin and oral mucosa were ...	1998	9827634
effects of peripheral nerve implants on the regeneration of partially and fully innervated urodele forelimbs.	this study addresses the cellular mechanism of the nerve requirement for regeneration of the urodele forelimb. others have suggested that only the schwann cell lineage of the blastema requires nerves for regeneration and that upon limb denervation, schwann cells arrest in the cell cycle and produce a factor that inhibits the cycling of the remaining blastema cells. our objective was to test this schwann cell inhibitor model. first, pieces of peripheral nerve were implanted into partially denerva ...	2006	9824557
on the conservation of calcium wave speeds.	most long distance calcium signals are believed to take the form of actively propagated calcium waves. in 1991, when this proposal was first advanced, all such waves were thought to belong to one class, for which fertilization waves were the prototype. moreover, the speeds of such waves were found to be conserved at about 10 microns/s for primary fertilization waves and 30 microns/s for waves through fully active systems at 20 degrees c. in 1993, preliminary evidence for a second class of such w ...	1998	9793683
evidence for introduction of a variable g1 phase at the midblastula transition during early development in axolotl.	after fertilization in axolotl, the synchronous cell cleavages are triphasic (s, g2 and m phases). midblastula transition (mbt) begins at the ninth cleavage and is the consequence of lengthening of cell cycles. by spectrofluorometry and incorporation of 3h thymidine into the nuclear dna followed by autoradiography on individual cells, the time at which a g1 phase appears during early development was investigated. the present results show that the g1 phase was introduced for the first time at mbt ...	1998	9783475
three-dimensional reconstruction of live embryos using robotic macroscope images.	to determine the three-dimensional (3-d) shape of a live embryo is a technically challenging task. we show that reconstructions of live embryos can be done by collecting images from different viewing angles using a robotic macroscope, establishing point correspondences between these views by block matching, and using a new 3-d reconstruction algorithm that accommodates camera positioning errors. the algorithm assumes that the images are orthographic projections of the object and that the camera ...	1998	9735567
cloning, sequencing and expression of a novel homeobox gene axnox-1 from the mexican axolotl.	we have cloned and sequenced a cdna containing a homeobox gene, axnox-1, from a stage 18 axolotl embryonic cdna library which shows only moderate levels of similarity to other known homeobox genes. the nucleotide sequence of the cdna has an open reading frame for 335 amino acids and besides the homeodomain, there is an acidic domain and a proline-rich domain present in the protein. the transcripts for this gene are detectable at stage 4 of embryonic development and, hence, there is a good possib ...	1998	9714797
anterior/posterior influences on neural crest-derived pigment cell differentiation.	the neural crest of vertebrate embryos has been used to elucidate steps involved in early embryonic cellular processes such as differentiation and migration. neural crest cells form a ridge along the dorsal midline and subsequently they migrate throughout the embryo and differentiate into a wide variety of cell types. intrinsic factors and environmental cues distributed along the neural tube, along the migratory pathways, and/or at the location of arrest influence the fate of neural crest cells. ...	1998	9711533
expression of hoxd genes in developing and regenerating axolotl limbs.	hox genes play a critical role in the development of the vertebrate axis and limbs, and previous studies have implicated them in the specification of positional identity, the control of growth, and the timing of differentiation. axolotl limbs offer an opportunity to distinguish these alternatives because the sequence of skeletal differentiation is reversed along the anterior-posterior axis relative to that of other tetrapods. we report that during early limb development, expression patterns of h ...	1998	9705229
effect of calcium on development of amiloride-blockable na+ transport in axolotl in vitro.	the axolotl, ambystoma mexicanum, which has no specific calcium-containing sieve layer in the dermis, provides useful material for the study of the effect of ca2+ on the development of amiloride-blockable active na+ transport across the skin of amphibians. we raised axolotls in thyroid hormone or aldosterone or cultured the skin with corticoid plus one of several ca2+ concentrations and found that 1) although the short-circuit current (scc) was increased by both aldosterone and 3,3',5-triiodo-l- ...	1998	9688962
post-transcriptional control of c-myc rna during early development analyzed in vivo with a xenopus-axolotl heterologous system.	we have set up a heterologous in vivo system to study gene regulation at the post-transcriptional level during early development. this system uses two amphibian species, xenopus laevis and ambystoma mexicanum (axolotl), the development of which is three to four times slower than that of x. laevis. the stability of three different synthetic x. laevis c-myc transcripts was followed after injection into fertilized axolotl eggs. one transcript is 2.2 kilobases (kb) long (full-length). the second is ...	1998	9674116
cloning and sequencing of the cdna for an rna-binding protein from the mexican axolotl: binding affinity of the in vitro synthesized protein.	a full length cdna for an rna-binding protein (axolotl rbp) with consensus sequence (rnp-cs) from the mexican axolotl, ambystoma mexicanum, has been cloned from a subtraction library. in vitro translation with synthetic mrna and subsequent hybrid-arrested translation with a specific antisense oligonucleotide confirms that the axolotl rbp cdna encodes an approx. 16 kda polypeptide. computer-assisted analyses revealed amino acid similarities of 58-60% to various rna-binding proteins and a 90 amino ...	1998	9655917
[study of amphibian brain asymmetry during normal embryonic and larval development].	amphibian embryos (triturus vulgaris, pleurodeles waltl, hynobius keyserlingii, ambystoma mexicanum, rana temporaria, bufo bufo, and xenopus laevis) were investigated. we ascertained the morphological right-side asymmetry of the brain, which appears at the neurula stage and is preserved during the postembryonic (larval) development. in t. vulgaris, p. waltl, h. keyserlingii, and x. laevis, we observed right-side asymmetry of peripheral analyzers, such as the retina, ganglia of nerve viii, and ol ...	1998	9644914
axolotl (ambystoma mexicanum) lymphocytes produce and are growth-inhibited by transforming growth factor-beta.	recombinant (r)tgf-beta 5, an isoform of tgf-beta thus far identified only in the frog, xenopus' laevis, inhibited phytohemagglutinin (pha)-induced mitogenesis of salamander (axolotl) splenocytes and thymocytes, and t cell growth factor-induced proliferation of splenic lymphoblasts. this inhibition could be reversed by incubating (r)tgf-beta 5 with an anti-tgf-beta 5 antibody, but not with an antibody directed against tgf-beta 2, another xenopus-produced tgf-beta isoform. acid-treated supernatan ...	2007	9617586
the heart of metamorphosing mexican axolotl but not that of the cardiac mutant is associated with the upregulation of hox a5.	the mexican axolotl (ambystoma mexicanum) is a facultative neotene which rarely undergoes metamorphosis in the wild. we now report for the first time a dramatic increase in the expression of hoxa5 in axolotl hearts as determined by rt-pcr and in situ hybridization analyses during spontaneous metamorphosis. the mexican axolotl has a naturally occurring mutation called gene c which allows hearts in homozygous (c/c) embryos to form but never to beat. rt-pcr analysis has not shown any significant di ...	1998	9588186
structure, diversity, and repertoire of vh families in the mexican axolotl.	the mexican axolotl v(h) segments associated with the igh c mu and c nu isotypes were isolated from anchored pcr libraries prepared from spleen cell cdna. the eight new v(h) segments found bring the number of v(h) families in the axolotl to 11. each v(h) had the canonical structural features of vertebrate v(h) segments, including residues important for the correct folding of the ig domain. the distribution of ser agc/t (agy) and tcn codons in axolotl v(h) genes was biased toward agy in complemen ...	1998	9570539
regulation of homeobox-containing genes during lens regeneration.	in this study, the expression of homeobox-containing genes was evaluated after lentectomy in the newt, which is competent for lens regeneration, and in the axolotl which is not. such a comparison was designed to offer insights about possible regulation due to regenerative abilities. six homeobox-containing genes were examined: nvhox a4, nvhox b1, nvhox 7, nvhox x, nvmsx-1 and xbr1. for all genes examined, it was found that soon after lentectomy in the newt there was a general down-regulation in ...	1998	9533863
cellular plasticity among axolotl neural crest-derived pigment cell lineages.	many of the factors and mechanisms guiding the migration/differentiation of neural crest cells that give rise to a number of distinguishable cell types, including all dermal and epidermal pigment cells, remain unknown. the axolotl possesses three pigment cell types that differentiate according to specific developmentally programmed sequences and contribute to pigment pattern in the adult. a single lineage of the crest that becomes restricted to one of three pigment cell types gives us the opport ...	1998	9523334
immunolocalization of aromatic l-amino acid decarboxylase, tyrosine hydroxylase, dopamine, and serotonin in the forebrain of ambystoma mexicanum.	to improve basic knowledge about the neurochemical organization of the urodele brain, and to study discrepancies in the localization of monoaminergic markers, we immunohistochemically charted the distribution of four such markers (tyrosine hydroxylase, aromatic l-amino acid decarboxylase, dopamine, and serotonin) in the axolotl (ambystoma mexicanum) forebrain. catecholaminergic and serotoninergic systems were found in similar locations to those seen in other urodela. as seen in other vertebrates ...	1998	9518271
wide tissue distribution of axolotl class ii molecules occurs independently of thyroxin.	unlike most salamanders, the mexican axolotl (ambystoma mexicanum) fails to produce enough thyroxin to undergo anatomical metamorphosis, although a "cryptic metamorphosis" involving a change from fetal to adult hemoglobins has been described. to understand to what extent the development of the axolotl hemopoietic system is linked to anatomical metamorphosis, we examined the appearance and thyroxin dependence of class ii molecules on thymus, blood, and spleen cells, using both flow cytometry and ...	1998	9510551
molecular biology of heart development in the mexican axolotl, ambystoma mexicanum.		1997	9505339
molecular cloning from neurulating ambystoma mexicanum embryos of the cdna encoding an orphan nuclear receptor (ador1) closely related to tr2-11.	we have isolated a cdna encoding a novel orphan nuclear receptor, ador1, closely related to testicular receptor-2 (tr2) orphan receptor family members, from neurulating ambystoma mexicanum embryos. the cdna sequence predicts a protein primary sequence of 416 amino acids with a calculated molecular weight of 45.8 kda. while the dna-binding domains of ador1 and htr2-11 share 96% identity, considerable divergence is observed at both extremities of the peptides. at the n-terminus, ador1 is 66% ident ...	1997	9503600
transferrin is necessary and sufficient for the neural effect on growth in amphibian limb regeneration blastemas.	cell proliferation during the early phase of growth in regenerating amphibian limbs requires a permissive influence of nerves. based on analyses of proliferative activity in denervated blastemas, it was proposed that nerves provide factors important for cells to complete the proliferative cycle rather than for mitogenesis itself. one such factor, the iron-transport protein transferrin (tf), is abundant in regenerating peripheral nerves where it is axonally transported and released at growth cone ...	1997	9493827
cloning of a complementary dna encoding an ambystoma mexicanum metallothionein, ammt, and expression of the gene during early development.	we have used a polymerase chain reaction strategy to isolate a metallothionein (mt) cdna from the amphibian ambystoma mexicanum (axolotl). this cdna is 875-bp long and encodes a 60 amino acid protein, ammt, typical for family 1 mts. it contains 20 cysteine (cys) residues that can be aligned with those of other vertebrate mts. the overall structure of the protein is unique among vertebrates in having only two amino acid residues before the first cys at the amino-terminal end. northern analyses sh ...	1998	9468225
abnormal limb regeneration in the short-toes mutant of the axolotl, ambystoma mexicanum: studies of age, level of amputation, and extracellular matrix.	limb regeneration in the short-toes axolotl is impaired. our goal was to characterize the regeneration process in this mutant by histological and immunocytochemical methods. previous research indicates that age and a defective basement membrane may be instrumental factors in short-toes axolotl regeneration (del rio-tsonis et al. [1992] proc. natl. acad. sci. u.s.a., 89:5502-5506). the present results show that limb regeneration can occur even in older (1-2-year-old) short-toes axolotls. the proc ...	1997	9399429
adaptive evolution via a major gene effect: paedomorphosis in the mexican axolotl.	although adaptive evolution is thought to depend primarily on mutations of small effect, major gene effects may underlie many of the important differences observed among species in nature. the mexican axolotl (ambystoma mexicanum) has a derived mode of development that is characterized by metamorphic failure (paedomorphosis), an adaptation for an entirely aquatic life cycle. by using an interspecific crossing design and genetic linkage analysis, a major quantitative trait locus for expression of ...	1997	9391174
hormone-induced rise in cytosolic ca2+ in axolotl hepatocytes: properties of the ca2+ influx channel.	calcium entry in nonexcitable cells occurs through ca(2+)-selective channels activated secondarily to store depletion and/or through receptor- or second messenger-operated channels. in amphibian liver, hormones that stimulate the production of adenosine 3',5'-cyclic monophosphate (camp) also regulate the opening of an ion gate in the plasma membrane, which allows a noncapacitative inflow of ca2+. to characterize this ca2+ channel, we studied the effects of inhibitors of voltage-dependent ca2+ ch ...	1997	9374637
the role of thyroid hormone in zebrafish and axolotl development.	exogenous thyroid hormone (th) induces premature differentiation of the zebrafish pectoral fins, which are analogous to the forelimbs of tetrapods. it accelerates the growth of the pelvic fins but not precociously. goitrogens, which are chemical inhibitors of th synthesis by the thyroid gland, inhibit the transition from larva to juvenile fish including the formation of scales, and pigment pattern; they stunt the growth of both pectoral and pelvic paired fins. inhibition by goitrogens is rescued ...	1997	9371791
taste disks are induced in the lingual epithelium of salamanders during metamorphosis.	morphological changes of oral cavity during metamorphosis with special reference to the taste organ were examined in ezo salamanders (hynobius retardatus) and axolotis (ambystoma mexicanum), and compared with those in bullfrogs (rana catesbeiana). the non-distensible tongue of salamanders changed the structure progressively during metamorphosis: a small area of the rostrum protruded and developed caudally with recession of the flat area of the tongue. the protrusion that developed on the tongue ...	1997	9363353
a primary cell culture model for defective cardiac myofibrillogenesis in mexican axolotl embryos.		1997	9358282
reduced epidermal expression of a pg-m/versican-like proteoglycan in embryos of the white mutant axolotl.	axolotl embryos have previously been used to study neural crest cell migration. in embryos of the normal wild type, neural crest cells migrate subepidermally to form pigment cells. in the trunk of the white mutant embryo, these cells are unable to migrate, possibly due to an inherited delay in the maturation of the local extracellular matrix. the present investigation reveals a reduced incorporation of [35s]sulfate into pg-m/versican-like proteoglycans synthesized in epidermal explants from the ...	1997	9344585
kinematics and efficiency of steady swimming in adult axolotls (ambystoma mexicanum)	the kinematics of steady swimming at a wide range of velocities was analysed using high-speed video recordings (500 frames s-1) of eight individuals of ambystoma mexicanum swimming through a tunnel containing stationary water. animals in the observed size range (0.1350.238 m total body length) prefer to swim at similar absolute speeds, irrespective of their body size. the swimming mechanism is of the anguilliform type. the measured kinematic variables the speed, length, frequency and ...	1997	9319776
abbreviated junctional sequences impoverish antibody diversity in urodele amphibians.	of the six complementarity-determining regions (cdr) forming the structure of the ab combining site, cdr3 of heavy chain is the most variable in length and sequence. diversity of this loop is determined by the number of gene segments involved, extent of addition to or deletion from the joining genes, and imprecision of the site of recombination. in neonatal mice and xenopus tadpoles, the last two factors occur less frequently than in adults, which in tadpoles result in low affinity ab responses ...	1997	9317138
structure and diversity of the heavy chain vdj junctions in the developing mexican axolotl.	the immune capacity of young and adult axolotls (ambystoma mexicanum) was evaluated by examining the combinatorial and junctional diversity of the vh chain. a large number of vdj rearrangements isolated from 2.5-, 3.5-, 10-, and 24-month-old animals were sequenced. six jh segments were identified with the canonical structure of all known vertebrate jhs, including the conserved trp103-gly104-x-gly106 motif. four core dh-like sequences were used by most (80%) of the vdj junctions. these g-rich seq ...	1997	9271630
melatonin levels in the gastrointestinal tissues of fish, amphibians, and a reptile.	melatonin was detected by radioimmunoassay in the gastrointestinal tract (git) of several species of fish (sturgeon, rainbow trout, carp), amphibians (axolotl, leopard frog, bullfrog), and one reptile (red-sided garter snake), which were sacrificed during the daytime. the highest levels of melatonin were detected in the snake [means = 1018 pg/g stomach, 328 pg/g proximal gut (pg), 511 distal gut (dg)] and carp (means = 102 pg/g stomach, 146 pg/g pg and 141 pg/g dg). lowest levels were found in t ...	1997	9204376
effects of urea on m4-lactate dehydrogenase from elasmobranchs and urea-accumulating australian desert frogs.	we measured the effect of urea on m4-lactate dehydrogenase (m4-ldh) from elasmobranchs and australian desert frogs (urea accumulators) and from two animals that do not accumulate urea, the axolotl and the rabbit. an analysis of the effect of urea on the kd(nadh), v, v/k(m(prr)) and v/k(m(nadh)) shows that in all cases the major effect of urea was on the binding of pyruvate, which fits with data in the literature that show that urea acts as a competitive inhibitor of ldh. the characteristics of t ...	1997	9180022
glial fibrillary acidic protein and vimentin in radial glia of ambystoma mexicanum and triturus carnifex: an immunocytochemical study.	the molecular characterization of glial lineage cells in two urodele species, ambystoma mexicanum and triturus carnifex, has been investigated immunocytochemically with antibodies directed against intermediate filament proteins, glial fibrillary acidic protein (gfap) and vimentin. ambystoma astroglia shows clear gfap-immunopositivity and vimentin-immunonegativity. the condition in triturus is quite the opposite, showing only a strong vimentin immuno-reaction. in these urodele brain the astroglia ...	1997	9176731
thyroid hormone receptor genes of neotenic amphibians.	since thyroid hormones play a pivotal role in amphibian metamorphosis we used pcr to amplify dna fragments corresponding to a portion of the ligand-binding domain of the thyroid hormone receptor (tr) genes in several neotenic amphibians: the obligatory neotenic members of the family proteidea the mudpuppy necturus maculosus and proteus anguinus as well as two members of the facultative neotenic ambystoma genus: the axolotl ambystoma mexicanum and the tiger salamander ambystoma tigrinum. in addit ...	1997	9169551
expression pattern of an axolotl floor plate-specific fork head gene reflects early developmental differences between frogs and salamanders.	gastrulation is one of the most important stages of animal development and, as such, tends to be remarkably conserved. therefore it is interesting to see that the two amphibian species, xenopus laevis (frog) and ambystoma mexicanum (axolotl), are different in the arrangement of cell types just before and during gastrulation. in xenopus, the cells that will form dorsal mesoderm are located deep in the dorsal marginal zone, while in the axolotl, these are on the surface of the embryo. in this stud ...	1997	9144925
insights into pigmentary phenomena provided by grafting and chimera formation in the axolotl.	the expression of pigmentation patterns in axolotl pigmentary mutants was observed following three types of experimental manipulations including chimera formation, reciprocal neural crest grafts, of gonadal primordia. three pigmentary genes were utilized including the wild type (d), white (d), and albino (a). in chimeras between white and albino embryos, melanoblasts from the white half crossed the graft interface to differentiate in albino skin. neural crest grafts from white embryos to albinos ...	1996	9125751
synaptic body movements in the sensory cells of lateral line organs in the urodele amphibian ambystoma mexicanum.	examination of the neuromasts in the tail of the living juvenile axolotl ambystoma mexicanum with interference contrast (nomarski) microscopy shows that their cellular structures can be identified in considerable detail. microscopy was performed with a 40 x water immersion objective or with a 100 x objective in a tail insertion chamber. thus the sensory hair bundles can be seen and their orientation can be determined. large spheres in the basal part of the sensory cells were predicted to be syna ...	1997	9119761
improved preservation of the subepidermal extracellular matrix in axolotl embryos using electron microscopical techniques based on cryoimmobilization.	the purpose of this metholdological survey was to find optimal methods for the fixation and demonstration of glycosaminoglycans, mainly hyaluronan, and proteoglycans, in subepidermal extracellular matrix (ecm) regions of axolotl embryos. we compared living ecm in the laser-scanning microscope (lsm) with chemically fixed or cryoimmobilized extracellular matrix in the transmission (tem) and scanning electron microscope (sem). the gel-like structure of living extracellular matrix in the lsm undoubt ...	1997	9087914
expression of integrins during axolotl limb regeneration.	limb regeneration in urodeles is achieved through the dedifferentiation of tissues at the amputation plane and through the production of the blastema. this tissue breakdown is possible by extensive alterations in molecules of the extracellular matrix. in this respect we describe the regulation of several integrins during such events. it was found that alpha 1 and beta 1 integrins were down-regulated as blastema formation proceeded. in contrast, the expression of alpha 3, alpha 6 and alpha v inte ...	1997	9079030
hypochord, an enigmatic embryonic structure: study of the axolotl embryo.	the hypochord of the axolotl embryo is first visible at an early tailbud stage, forming a rod-like structure, situated immediately under the notochord. a profusion of extracellular matrix fibrils is attached to the dorsolateral regions of the hypochord, linking it with the somites. a basal lamina develops around the hypochord, indicating an epithelial type of cell differentiation. abundant rough endoplasmic reticula in the hypochord cells suggest lively synthetic activity. prospective endoderm c ...	1997	9068201
evidence for the presence and participation of 85-75 kda extracellular matrix components in cell interactions of bufo arenarum gastrulation.	we studied the presence and distribution of the extracellular materials (ecm), obtained by mild embryonic dissociation through nondenaturing and denaturing page, immunoblotting and immunocytochemical wholemount in the gastrulation of anuran amphibian bufo arenarum. the sds-page, under reducing conditions, revealed the protein profile of the ecm which comprised six bands. the western immunoblotting effected with antibodies against fibronectins (fn) of xenopus laevis, ambystoma mexicanum and bufo ...	1997	9062995
differential expression of a novel isoform of alpha-tropomyosin in cardiac and skeletal muscle of the mexican axolotl (ambystoma mexicanum).	alternative mrna splicing is a fundamental process in eukaryotes that contributes to tissue-specific and developmentally regulated patterns of tropomyosin (tm) gene expression. northern blot analyses suggest the presence of multiple transcripts of tropomyosin in skeletal and cardiac muscle of adult mexican axolotls. we have cloned and sequenced two tropomyosin cdnas designated atmc-1 and atmc-2 from axolotl heart tissue and one tm cdna from skeletal muscle, designated atms-1. nucleotide sequence ...	1997	9055812
analysis of the three-dimensional distributions of alpha-actinin, ankyrin, and filamin in developing hearts of normal and cardiac mutant axolotls (ambystoma mexicanum).	alpha-actinin is an actin binding protein that assists in the stabilization of the plasma membrane and helps to fix organelles in position in a variety of cell types. in muscle, it is a major component of the z-lines of organized myofibrils. ankyrin binds to various elements of the cytoskeletal system including microtubules, microfilaments, and intermediate filaments and may help to anchor these structures to the cell membrane. filamin is a well-characterized actin-associated protein first isola ...	1997	9045985
isolation of mhc class i cdnas from the axolotl ambystoma mexicanum.	class i major histocompatibility complex (mhc) cdna clones were isolated from axolotl mrna by polymerase chain reaction (pcr) and by screening a cdna phage library. the nucleotide and predicted amino acid sequences show definite similarities to the mhc class ialpha molecules of higher vertebrates. most of the amino acids in the peptide binding region that dock peptides at their n and c termini in mammals are conserved. several amino acids considered to be important for the interaction of beta2-m ...	1997	9038100
regulation of intracellular ph in salamander retinal rods.	1. we measured intracellular ph (phi) in rods isolated from the retina of the axolotl salamander, ambystoma mexicanum, using the fluorescent indicator 2',7'-bis(carboxyethyl)-5(and -6)-carboxyfluorescein (bcecf). 2. the light exposures associated with data acquisition had no marked effect on phi. there was no sharp change between the value obtained from the first exposure of dark-adapted rods and subsequent readings. increasing the acquisition frequency from 1 to 10 min-1 either had no effect, o ...	1997	9023768
cardioventilatory responses to hypoxia and nacn in the neotenous axolotl.	ventilatory and cardiac responses to hypoxia, sodium cyanide (nacn), and intra-arterial injection of atropine, noradrenaline and dl-propranolol were investigated in the neotenous axolotl (ambystoma mexicanum). hypoxia elicited increased gill and lung ventilation and a tachycardia. gill ventilation and air-breathing were stimulated by nacn infused either into the ventilatory water stream or into the bloodstream. cardiac responses to nacn were complex, with an initial bradycardia followed by a tac ...	1996	9017844
pg-m/versican-like proteoglycans are components of large disulfide-stabilized complexes in the axolotl embryo.	large disulfide-stabilized proteoglycan complexes were previously shown to be synthesized by the epidermis of axolotl embryos during stages crucial to subepidermal migration of neural crest cells. we now show that the complexes contain pg-m/versican-like monomers in addition to some other component with low buoyant density. metabolically 35s-labeled proteoglycans were extracted from epidermal explants and separated by size exclusion chromatography and density equilibrium gradient centrifugation. ...	1997	9013561
structure and diversity of the t-cell receptor alpha chain in the mexican axolotl.	polymerase chain reaction was used to isolate cdna clones encoding putative t-cell receptor (tcr) alpha chains in an amphibian, the mexican axolotl (ambystoma mexicanum). five tcralpha-v chain-encoding segments were identified, each belonging to a separate family. the best identity scores for these axolotl tcralpha-v segments were all provided by sequences belonging to the human tcralpha-v1 family and the mouse tcralpha-v3 and tcralpha-v8 families. a total of 14 different tcra-j segments were id ...	1997	9002443
effects of the antiepileptic drug valproic acid on the development of the axolotl (ambystoma mexicanum): histological investigations.	in the amphibian ambystoma mexicanum, valproic acid (vpa) causes retarded development and malformations including neural tube defects. some of the observed abnormalities resemble exencephaly. we present the light microscopic characteristics of vpa-induced effects on the developing central nervous system (cns) as well as on other developing tissues of this species. to induce malformations, various concentrations of vpa were applied to embryos from blastula stage on, either as 24-h pulse or as con ...	1996	8983118
a specific synthetic rna promotes cardiac myofibrillogenesis in the mexican axolotl.	ambystoma mexicanum is an intriguing animal model for studying heart development because it carries a mutation in gene c. hearts of homozygous recessive (c/c) mutant embryos do not contain organized myofibrils and fail to beat. however, the defect can be corrected by organ-culturing the mutant heart in the presence of rna from anterior endoderm or rna from endoderm mesoderm-conditioned medium. we constructed a cdna library from total conditioned medium rna in a pcdnaii expression vector. we scre ...	1996	8955002
nerve dependency of regeneration: the role of distal-less and fgf signaling in amphibian limb regeneration.	dlx-3, a homolog of drosophila dll, has been isolated from an axolotl blastema cdna library, and its expression in developing and regenerating limbs characterized. the normal expression pattern, and the changes that occur during experimental treatments, indicate a correlation between dlx-3 expression and the establishment of the outgrowth-permitting epidermis. dlx-3 is expressed at high levels in a distal-to-proximal gradient in the epidermis of developing limb buds, and is upregulated in the ap ...	1996	8951064
expression of myosin heavy chain transcripts in normal and cardiac mutant mexican axolotls.	in this study, we have cloned a 1.0 kb myosin heavy chain (mhc) cdna by screening an axolotl heart cdna library with the monoclonal antibody mf20 against a light meromyosin (lmm) region of mhc. the nucleotide sequence analysis shows 85-86% homology at the amino acid and 78-81% homology at the nucleic acid level with mhc from other vertebrates. phylogenetic analyses suggest that axolotl beta-mhc forms a cluster with the myosin ii group of vertebrate striated muscles. within the myosin ii cluster, ...	1996	8932525
influence of insulin-like growth factors and insulin on the [35s]sulfate uptake by cartilage of the axolotl (ambystoma mexicanum).	the actions of mammalian insulin-like growth factors (igf-i and igf-ii) and insulin on skeletal growth of the axolotl, ambystoma mexicanum, were examined by monitoring the in vitro uptake of [35s]sulfate by cartilage. both growth factors stimulated sulfate uptake significantly at a concentration of 13 nm. the increase after incubation with 130 nm insulin was similar (uptake ca. 160% of control), but the effect was not significant. further, the binding of 125i-igf-i and 125i-igf-ii was studied in ...	1996	8921360
histochemistry and role of nitric oxide synthase in the amphibian (ambystoma tigrinum) inner ear.	nicotinamide adenine dinucleotide phosphate reduced-diaphorase (nadph-d) histochemistry was investigated in the axolotl (ambystoma tigrinum) inner ear. hair cells showed an intense nadph-d reaction; afferent neurones also stained but less intensely than hair cells. effects of ng-nitro-l-arginine (l-noarg) on the basal discharge and mechanical responses of semicircular canal afferent neurones recorded extracellularly were also studied. l-noarg (1 mu m) diminished the basal discharge and the respo ...	1996	8907334
activation by mitogens and superantigens of axolotl lymphocytes: functional characterization and ontogenic study.	urodele amphibians have weak and slow immune responses compared to mammals and anuran amphibians. using new culture conditions, we tested the ability of lymphocytes of a well-studied salamander, the mexican axolotl (ambystoma mexicanum) to proliferate in vitro with diverse mitogenic agents. we demonstrated that the axolotl has a population of b lymphocytes that proliferate specifically and with a high stimulation index to the lipopolysaccharide (lps) known as a b-cell mitogen in mammals. this pr ...	1996	8881761
how to observe surface contraction waves on axolotl embryos.		1996	8877469
treatment of axolotls with retinoids for limb regeneration studies.		1996	8877467
a method for the isolation and culture of embryonic cardiomyocytes from mexican axolotl.		1996	8877466
urodele (e.g., axolotl) embryos in the undergraduate laboratory class: an essay describing a multifaceted learning experience.		1996	8877465
axolotls in the second grade.		1996	8877463
what insights into the developmental traits of urodeles does the study of interspecific hybrids provide?	natural and artificial hybrids represent an important source of material for developmental and evolutionary studies of urodeles. we review the available literature on hybrid salamanders, emphasizing the unique developmental insights that these organisms provide. of particular interest is the application of new molecular tools to identify dna markers for traditional characters in developmental research, and we discuss our own results using bulk segregant analysis to identify rapd markers for the ...	1996	8877462
molecular mechanisms in the control of limb regeneration: the role of homeobox genes.	axolotls are unique among vertebrates in their ability to regenerate lost appendages as adults. they provide the opportunity to study the mechanism of regeneration in vertebrates and are an inspiration to pursue the goal of appendage regeneration in humans. in this article, we review data on the role of homeobox-containing genes in the regulation of limb regeneration. as a group, these genes are important in pattern formation in the primary body axis, developing limbs and regenerating limbs. to ...	1996	8877453
lens induction in axolotls: comparison with inductive signaling mechanisms in xenopus laevis.	amphibian lens induction is an embryonic process whose broad outlines are conserved between anurans and urodeles; however, it has been argued that some aspects of this process differ significantly between even closely related species. classical embryologists concluded that in some species direct contact between the optic vesicle and ectoderm was both necessary and sufficient to induce the ectoderm to form a lens, while in other species tissues other than the optic vesicle induce lens formation. ...	1996	8877449
morphogenesis of the axolotl pronephric duct: a model system for the study of cell migration in vivo.	pronephric duct (pnd) morphogenesis is a critical early event in the development of the vertebrate excretory system. this structure is the exit channel for both pronephric and mesonephric filtrate, forms the ureteric bud of the metanephros and gives rise to the ductus deferens of the testis. in addition, the pnd and ureteric bud epithelia induce terminal differentiation of the mesonephric and metanephric mesenchyme, respectively. elongation of the pnd in all vertebrates involves active cell migr ...	1996	8877443
what insights into vertebrate pigmentation has the axolotl model system provided?	amphibians have been judiciously exploited by developmental biologists for many years for studying basic developmental mechanisms in vertebrates. in this review, the contributions that have been made by urodeles, in particular the axolotl (ambystoma mexicanum), to the study of pigment cell biology are elaborated. pigment cell differentiation is described, and the wild-type pigment phenotype is contrasted to pigment mutants such as albino, axanthic, melanoid, and white. methods used for studying ...	1996	8877441
what mechanisms control neoteny and regulate induced metamorphosis in urodeles?	the mexican axolotl, like a number of other urodele species, is an obligatory neotene, completing its full life cycle without metamorphosis. metamorphosis can be induced with thyroid hormone, thyroid stimulating hormone, or stimulation of hypothalamic neurons. thus, neoteny represents a deviation from the standard course of amphibian ontogeny, affecting the thyroid axis at one or more levels. analysis of the thyroid axis at strategic ontogenic stages and after completed neotenic development sugg ...	1996	8877439
surface contraction and expansion waves correlated with differentiation in axolotl embryos. ii. in contrast to urodeles, the anuran xenopus laevis does not show furrowing surface contraction waves.	we have observed a number of contraction waves traversing the axolotl (ambystoma mexicanum) embryo (a urodelan amphibian) from the midblastula transition up to at least neural tube closure, and wished to learn if similar "differentiation waves" appear on the popular laboratory anuran amphibian, the south african clawed toad, xenopus laevis. time lapse video microscopy showed that no contraction waves are visible on the surface of xenopus from gastrulation through neurulation. it is possible that ...	1996	8877438
differential expression of c-protein isoforms in the developing heart of normal and cardiac lethal mutant axolotls (ambystoma mexicanum).	regulated assembly of contractile proteins into sarcomeric structures, such as a- and i-bands, is still currently being defined. the presence of distinct isoforms of several muscle proteins suggests a possible mechanism by which myocytes regulate assembly during myofibrillogenesis. of several muscle isoforms located within the a-band, myosin binding proteins (mybp) are reported to be involved in the regulation and stabilization of thick filaments during sarcomere assembly. the present confocal s ...	1996	8834470
the cardiac mutant gene c in axolotls: cellular, developmental, and molecular studies.	the cardiac mutant axolotl is an interesting model for studying heart development. the mutant gene results in a failure of heart cells to form organized myofibrils and as a consequence the heart fails to beat. experiments have shown that mutant hearts can be "rescued" (i.e., turned into normally contracting organs) by the addition of rna purified from conditioned media produced by normal embryonic anterior endoderm-mesoderm cultures. these corrected hearts form myofibrils of normal morphology. n ...	1995	8775986
the structure, rearrangement, and ontogenic expression of db and jb gene segments of the mexican axolotl t-cell antigen receptor beta chain (tcrb).	we sequenced a total of 189 independent rearrangements in which the vb7.1 element is associated with cb1 (99 clones) or cb2 (90 clones) isotypes of the t-cell receptor (tcr) beta chain in the mexican axolotl. three stages of development were analyzed: 2.5 months, 10 months, and 25 months. three jb1 segments were associated with the vb-cb1 rearrangements and six jb2 segments with vb-cb2. as in other vertebrates, some amino acid positions were conserved in all jbetas (e. g., phe-108, gly-109, gly- ...	1996	8753858
effects of extracellular matrix molecules on subepidermal neural crest cell migration in wild type and white mutant (dd) axolotl embryos.	migration of neural crest (nc) derived pigment cells is restricted in the white mutant (dd) axolotl embryo (ambystoma mexicanum). transplantations between mutant and wild type embryos show that the extracellular matrix (ecm) of the white mutant is unable to support the migration of prospective pigment cells in wild type embryos (löfberg et al., 1989, dev. biol. 131:168-181). in the present study, we test the effects of various purified ecm molecules on nc cell migration in the subepidermal migra ...	1996	8739557
distribution of keratan sulphate and chondroitin sulphate in wild type and white mutant axolotl embryos during neural crest cell migration.	in embryos of the white mutant axolotl, prospective pigment cells are unable to migrate from the neural crest (nc) due to a deficiency in the subepidermal extracellular matrix (ecm). this raises the question of the molecular nature of this functional defect. some pgs can inhibit cell migration on ecm molecules in vitro, and an excess of this class of molecules in the migratory pathways of neural crest cells might cause the restricted migration of prospective pigment cells seen in the white mutan ...	1996	8739556
nucleotide sequence and expression of ribosomal protein s3 mrna during embryogenesis in the mexican axolotl (ambystoma mexicanum).	we have isolated and sequenced a full-length (0.9 kb) cdna clone of ribosomal protein s3 by subtraction hybridization using a single-stranded cdna library from stage 25-27 (tracer) and the mrna from stage 15-17 (driver) of embryonic mexican axolotl (ambystoma mexicanum). the axolotl is a unique animal model for studying heart development as well as myofibrillogenesis because it carries a mutation in gene c. the deduced amino acid sequence of axolotl s3 protein shows about 93.9% identity with hum ...	1996	8739028
neural crest cell migration and pigment pattern formation in urodele amphibians.	this review deals with research on the development and differentiation of the neural crest (nc) in amphibians carried out during the past twenty years. first, earlier studies on the migration and differentiation of nc cells in vitro are summarized. these studies include the modes of nc cell migration and their differentiation into chondroblasts, perichondral cells, neurons, schwann cells and pigment cells (melanophores and xanthophores). then a summary is given on the development of cranial sens ...	1996	8735933
antagonism of glutamate receptors by a chromatographic fraction from the exudate of the sea anemone phyllactis flosculifera.	in the search for new glutamate antagonists it seems promising to characterize the effects of venom from invertebrates that prey mainly on crustaceans. in this work, the exudate of the sea anemone phyllactis flosculifera was used as a source of this type of compound. the action of chromatographic fraction d from p. flosculifera was tested upon microion-tophoretically evoked glutamate responses in intracellular recordings from central neurons of the land snail zachrysia guanensis. bath applicatio ...	1996	8735243
hard tissue of teeth and their calcium and phosphate content in ambystoma mexicanum (urodela: ambystomatidae).	the wall of the pulp cavity, fracture faces and the demineralized surfaces of teeth from larvae and adults of ambystoma mexicanum were investigated by scanning electron microscopy (sem). calcium and phosphate contents were determined by microanalysis. the apical part of the tooth (crown, tooth apex) contains dentin canals. in the larva, these do not reach the enamel-dentin border but end below this border in front of a denser hard substance, possibly enameloid. the pedicel in the adult and the b ...	1996	8717330
identification of cdna clones encoding hmg 2, a major protein of the mexican axolotl hydrocortisone-sensitive thymocytes.	we have identified and analyzed cdna clones encoding a major 26 kda protein of the hmg1-2 family which is abundant in the cytoplasm and nucleus of axolotl hydrocortisone-sensitive thymocytes. the axolotl hmg2 protein is very similar to proteins belonging to the hmg1-2 family, from teleost fish to mammals. all the molecular features of the hmg1-2 proteins are conserved, including the high proportion of basic and aromatic residues, and the characteristic acidic c-terminus tail. the 3'-untranslated ...	2003	8654668
embryonic taste buds develop in the absence of innervation.	it has been hypothesized that taste buds are induced by contact with developing cranial nerve fibers late in embryonic development, since descriptive studies indicate that during embryonic development taste cell differentiation occurs concomitantly with or slightly following the advent of innervation. however, experimental evidence delineating the role of innervation in taste bud development is sparse and equivocal. using two complementary experimental approaches, we demonstrate that taste cells ...	1996	8620837
the epidermis is a source of directional information for the migrating pronephric duct in ambystoma mexicanum embryos.	in the urodele ambystoma mexicanum, the pronephric duct (pnd) is formed from a coherent group of cells that migrate from the pronephros to the cloaca along a pathway immediately ventral to the developing somites. the guidance cues used by the migrating pnd primordium to find the cloaca are a local property of the migration substratum, are temporally regulated, and are both polarized and oriented. since the pronephric duct migrates between two tissues--the underlying lateral mesoderm and the over ...	1995	8612962
in vivo protein synthesis in developing hearts of normal and cardiac mutant axolotls (ambystoma mexicanum).	recessive mutant gene c in axolotls causes a failure of the hearts of affected embryos to function. the mutant hearts (c/c) lack organized sarcomeric myofibrils. the present study was undertaken to determine the overall pattern of in vivo protein synthesis and subsequent accumulation of the newly synthesized proteins for a 24-h period in normal (+/+ or +/c) and cardiac mutant (c/c) axolotl hearts at various stages of development. additionally, selected cytoskeletal/myofibrillar proteins were ana ...	1995	8589758
immunohistochemical analysis of c-protein isoforms in cardiac and skeletal muscle of the axolotl, ambystoma mexicanum.	of the several proteins located within sarcomeric a-bands, c-protein, a myosin binding protein (mybp) is thought to regulate and stabilize thick filaments during assembly. this paper reports the characterization of c-protein isoforms in juvenile and adult axolotls, ambystoma mexicanum, by means of immunofluorescent microscopy and western blot analyses. c-protein and myosin are found specifically within the a-bands, whereas tropomyosin and alpha-actin are detected in the i-bands of axolotl myofib ...	1995	8581934
confocal microscopy of a newly identified protein associated with heart development in the mexican axolotl.	recessive mutant gene c for "'cardiac nonfunction" in the mexican axolotl, ambystoma mexicanum, results in a failure of affected embryos to develop contracting hearts. mutant embryos survive approximately 4 weeks after fertilization, but eventually die from a lack of circulation. morphological studies show that mutant hearts lack organized sarcomeric myofibrils. this abnormality can be corrected by co-culturing early mutant hearts with normal anterior endoderm/mesoderm tissues, by culturing them ...	1995	8581063
activin a and transforming growth factor-beta stimulate heart formation in axolotls but not rescue cardiac lethal mutants.	in the mexican axolotl (salamander), ambystoma mexicanum, a recessive cardiac lethal mutation causes an incomplete differentiation of the myocardium. mutant hearts lack organized sarcomeric myofibrils and do not contract throughout their lengths. we have previously shown that rna purified from normal anterior endoderm or from juvenile heart tissue is able to rescue mutant embryonic hearts in an in vitro organ culture system. under these conditions as many as 55% of formerly quiescent mutant hear ...	1995	8565053
characterization of an ultraviolet photoreception mechanism in the retina of an amphibian, the axolotl (ambystoma mexicanum).	spectral sensitivity measurements from the retina of the mexican salamander ambystoma mexicanum (the 'axolotl') were used to provide evidence for and to characterize an amphibian ultraviolet-sensitive photoreception mechanism. electroretinograms (transretinal voltage responses) were recorded from open eye cup preparations to analyze the spectral sensitivity of the retina. both dark-adapted and white light-adapted preparations exhibited a peak in sensitivity between 360-370 nm. under selective ch ...	1995	8552288
regeneration of sensory cells after laser ablation in the lateral line system: hair cell lineage and macrophage behavior revealed by time-lapse video microscopy.	the regeneration of sensory hair cells in lateral line neuromasts of axolotls was investigated via nearly continuous time-lapse microscopic observation after all preexisting hair cells were killed by a laser microbeam. the laser treatments left neuromasts with one resident cell type, which was supporting cells. over the course of 1 week, replacement hair cells arose either directly via differentiation of cells present in the epithelium from the beginning of the time-lapse period or via the devel ...	1996	8551349
molecular analysis of the wnt-1 proto-oncogene in ambystoma mexicanum (axolotl) embryos.	to analyze wnt-1 expression during neurulation in urodele embryos, we have isolated a wnt-1 cdna clone, awnt-1, from an ambystoma mexicanum (axolotl) neurula-stage cdna library. awnt-1 codes for a protein of 369 amino acids rich in cysteine residues, is preceded by a hydrophobic leader peptide sequence and contains four possible sites for n-linked glycosylation. the temporal expression profile of awnt-1 was analyzed by reverse transcription-polymerase chain reaction (rt-pcr). awnt-1 expression i ...	1993	8508949
brachially innervated ectopic hindlimbs in the chick embryo. i. limb motility and motor system anatomy during the development of embryonic behavior.	the functional status of brachially innervated hindlimbs, produced by transplanting hindlimb buds of chick embryos in place of forelimb buds, was quantified by analyzing the number and temporal distribution of spontaneous limb movements. brachially innervated hindlimbs exhibited normal motility until e10 but thereafter became significantly less active than normal limbs and the limb movements were more randomly distributed. contrary to the findings with axolotls and frogs, functional interaction ...	1993	8492107
afferent and efferent connections of the thalamic eminence in the axolotl, ambystoma mexicanum.	afferent and efferent connections of the thalamic eminence of the axolotl were determined using the fluorescent compound dii as a tracer. the thalamic eminence is connected reciprocally with a number of telencephalic and diencephalic areas, particularly with the medial pallium, the amygdala and the preoptic region. efferent connections are widespread throughout the ipsilateral diencephalon. these findings are discussed in relation to the homology of this nucleus, especially its homologue in agna ...	1993	8474688
immunocytochemical identification of serotonin-synthesizing neurons in the vertebrate retina: a comparative study.	serotonin-synthesizing neurons in the retinas of goldfish, axolotl, turtle, chick, rabbit and cat were identified using double labelling with anti-serotonin and anti-phenylalanine hydroxylase antibodies. the latter antibody recognizes tryptophan 5-hydroxylase, one of the synthesizing enzymes for serotonin. neurons labelled by both markers were considered to be serotonin-synthesizing neurons, while those only with serotonin-immunoreactivity were assumed to be serotonin-accumulating neurons. in th ...	1993	8462655
isolation of cdnas for two closely related members of the axolotl wnt family, awnt-5a and awnt-5b, and analysis of their expression during development.	to characterize molecular interactions between cells in the early amphibian embryo, we have isolated cdnas for two members of the axolotl (ambystoma mexicanum) wnt family, awnt-5a and awnt-5b. the encoded proteins share 83% amino acid identity. using a reverse transcription-polymerase chain reaction (rt-pcr) assay, we find that awnt-5a transcripts are abundant in the blastula until gastrulation, barely detectable during gastrulation, and increase again during neurulation. they are detected throu ...	1993	8443107
replacement of lateral line sensory organs during tail regeneration in salamanders: identification of progenitor cells and analysis of leukocyte activity.	it has been proposed that supporting cells may be the progenitors of regenerated hair cells that contribute to recovery of hearing in birds, but regeneration is difficult to visualize in the ear, because it occurs deep in the skull. hair cells and supporting cells that are comparable to those in the ear are present in lateral line neuromasts, and in axolotl salamanders these cells are accessible to microscopic observation in vivo. after amputation of a segment of the tail that contains neuromast ...	1993	8441001
metamorphic changes in glycolipids and myelin proteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase in bullfrog and axolotl brains.	the metamorphic changes in levels of glycolipids and myelin proteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase (cnp) in the brains of bullfrog tadpoles, adult frogs, and axolotls were investigated, with particular emphasis on myelin maturation. the concentrations of cerebroside, sulfatide, and galactosyldiacylglycerol gradually increased from the onset of prometamorphosis throughout the active metamorphic period and then greatly increased after metamorphosis was completed. the ratio of glu ...	1993	8386225